Nutritional Management of Disease: Medical Nutrition Therapy That Changes Outcomes
This domain tests whether you can convert a diagnosis into a specific energy, protein, sodium or fluid prescription and adjust it as the patient changes. Items concentrate on diabetes, hypertension, chronic kidney disease, liver and gastrointestinal disease, and critical care, where the numbers matter more than the general advice.
Diabetes
Set energy to achieve or maintain a healthy weight. Carbohydrate 45-60% of energy, favouring low-glycaemic-index whole grains; fibre 25-30 g/day; protein 15-20% (about 0.8-1.0 g/kg); fat below 30% with saturated fat below 10%; salt below 5 g/day. Teach consistent carbohydrate distribution and carbohydrate counting. For hypoglycaemia, give 15 g of fast-acting carbohydrate and recheck glucose after 15 minutes.
Hypertension and cardiovascular disease
Sodium below 2000 mg/day (salt below 5 g), a DASH-style pattern rich in potassium, magnesium, calcium and fibre, weight loss, limited alcohol, and replacement of saturated with unsaturated fat.
Chronic kidney disease
Non-dialysis: protein 0.6-0.8 g/kg/day with at least 50% high biological value, energy 30-35 kcal/kg, phosphorus 800-1000 mg/day, sodium below 2 g, potassium individualised on serum levels. Dialysis: protein rises to 1.0-1.2 g/kg/day because amino acids are lost in the dialysate. Energy must be adequate or dietary protein is burned as fuel.
Liver and gastrointestinal disease
Cirrhosis: 35-40 kcal/kg and 1.2-1.5 g/kg protein, a late-evening snack to blunt nocturnal catabolism, sodium restriction for ascites, and absolute alcohol avoidance. Acute pancreatitis: begin oral or enteral feeding early once pain and ileus resolve; prolonged clear-liquid starvation is outdated. Inflammatory bowel disease: no single therapeutic diet, but screen for iron, vitamin B12, folate and vitamin D.
Critical care
Start enteral nutrition within 24-48 hours when the gut works; target 25-30 kcal/kg and 1.2-2.0 g/kg protein. In shock use trophic feeding and advance as stability returns. For refeeding risk, start at 10-20 kcal/kg, give thiamin before or with feeding, and monitor potassium, magnesium and phosphate.
Worked example
A 60 kg woman with stage 3 CKD: protein 0.6-0.8 g/kg gives 36-48 g/day; energy 30-35 kcal/kg gives 1800-2100 kcal. If her actual intake is only 1200 kcal, the prescribed protein will be oxidised for energy and she will lose muscle - so energy is fixed first, then protein is titrated, and phosphorus binders are reviewed with the diet.
Traps that cost marks
Restricting protein in dialysis patients as if they were non-dialysis. Forgetting thiamin and phosphate in refeeding syndrome. Restricting potassium in every CKD patient regardless of serum values. Using serum albumin to decide protein needs instead of weight and clinical state.